There’s no doubt that exercise is good for you. From maintaining a healthy weight and blood pressure to boosting your self- esteem and mental health, the positive aspects of keeping fit are endless. As with most things, there can be too much of a good thing, and excessive exercise can have a detrimental effect on your health also. It’s hard to quantify exactly how much exercise is “excessive” or how much weight loss is significant – as with most things, it will vary with the individual. Despite this, I think it’s safe to say that marathon training could easily fall into the excessive category, and for some people, have a negative impact on their health.
A relatively common complaint among female marathon runners is amenorrhoea, which is the medical term used to describe the absence of regular periods for 6 months or longer. There’s a long list of reasons why your periods may stop, so it always needs to be investigated by a doctor to look for a more serious underlying cause. In this article I’m just going to discuss the affect of exercise and weight on your periods.
WHY DOES EXERCISE STOP YOUR PERIODS?
In the brain there’s an almond- sized gland called the hypothalamus, which plays an important role in the body’s internal balance, or homestasis. It releases a host of hormones, which help maintain your normal body processes, such as body temperature, metabolism, sleep cycles, and your menstrual cycle. It’s not clearly understood, but under certain conditions, such as when you exercise excessively or your body weight drops, the hypothalamus can stop functioning normally and stops producing the hormones which control your menstrual cycle, and hence, your periods stop.
SO, WHY DOES THIS MATTER?
A lack of periods can cause problems for both your mental and physical health, so it’s important to address it early. Here are a few of the common problems related to amenorrhoea:
First up is bone health. Osteoporosis is a bone disease which causes low bone mass and a breakdown in the structure of the bone. These changes make the bones more fragile and more likely to suffer a fracture. There aren’t usually any symptoms of osteoporosis, so it’s often not diagnosed until you’ve broken a bone. There are various factors which make osteoporosis more likely- some of these you can’t control, such as being female or older age. Studies, however, have shown that women with amenorrhoea related to oestrogen deficiency, such as those I described above, are at a higher risk of osteoporosis. Unfortunately, it’s also been shown that even if periods return to normal, the increased risk of osteoporosis is still there. Teenage girls are especially at risk because they may never have reached their full bone mass in the first place.
Next up, are fertility problems. If you’re not having periods, you’re probably not ovulating which makes it hard to conceive a pregnancy. This isn’t necessarily a problem if you’re not planning a family, but for those who are it can have a huge impact. Reassuringly, once your periods (and ovulation) return, you shouldn’t have any lasting problems trying to conceive.
For some women, it’s often the impact on their mental health which is more profound. It’s shown that women can feel a loss of femininity, anxiety, and loss of self- esteem when they’re not having periods.
WHAT CAN BE DONE ABOUT IT?
Once the cause of amenorrhoea has been identified there are various things you can do to help your periods return.
- Reduce exercise
First of all, don’t panic! It’s not a case of stopping exercise or running all together, but perhaps reducing your mileage or high- intensity sessions. If you’re an elite athlete or just really serious about your sport, it may be worth seeing a sports doctor for better guidance on this.
- Increase calorie intake
It’s easy to forget how many calories you burn while training for a marathon or training regularly. Try and increase your calorie intake to ensure you’re making up for the calories burned during exercise, as well eating your recommended daily allowance. (1500-2000 for women, 2000-2500 for men).
- Increase your weight.
By the nature of the sport, long distance runners often have a low body weight. By increasing your weight, you may find your periods return. I know for many people, this can be a struggle, so your GP should be able to refer you to a registered dietician to help you do this in a healthy way.
I hope this has been a useful read for the female readers out there. As I mentioned before, please see your GP if you think this problem applies to you and you’d like some help.
NICE Guidelines for Amenorrhoea, last revised July 2014
Warren, M.P. and Stiehl, A.L. (1999) Exercise and female adolescents: effects on the reproductive and skeletal systems. Journal of the American Medical Women’s Association 54(3), 115-120
Davies, M.C., Hall, M.L. and Jacobs, H.S. (1990) Bone mineral loss in young women with amenorrhoea. British Medical Journal301(6755), 790-793
Baird, D.T. (1997) Amenorrhoea. Lancet 350(9073), 275-279